A service area of a long term evolution (LTE) network is typically broken up into geographic regions known as tracking areas. An eNodeB (eNB) is composed of one or more cell sites and each cell site within an LTE network is associated with a tracking area. After user equipment (UE) is attached to an LTE network, the UE transmits a tracking area update (TAU) request when it detects that it has entered a tracking area where it is not registered. A mobility management entity (MME) of the LTE network receives the TAU requests and provides the UE with an updated list of tracking areas where it is now registered. In cases where the UE is at a border of two or more tracking areas, however, the UE may rapidly toggle between the cells of adjacent tracking areas. As the UE toggles, it may generate a TAU request each time it toggles between cells of the adjacent tracking areas. This phenomenon is known as the “ping-pong” effect. A UE exhibiting the “ping-pong” effect may generate a high number of TAU requests that may result in a drop in network capacity. Given the unusually high rate of TAU requests generated under these conditions, a relatively small number of UEs exhibiting this behavior may overwhelm a network with TAU requests. The increased message traffic and CPU usage required to handle the flood of TAU request messages may have a significant negative impact on overall network capacity.
A previous method of addressing the “ping-pong” effect involved allowing a service provider to provision a set of neighbor tracking areas associated with each tracking area. The MME would include the provisioned neighbor tracking areas in the list of registered tracking areas communicated to the UE. The UE would not send a TAU request when it passed through tracking areas comprising the neighbor tracking area list. This solution, however, greatly increases network resources devoted to paging because the area that the UE can move in without performing a TAU procedure is typically increased from, for example, two to sixteen tracking areas. A UE is typically paged in its last known tracking area; if the UE does not respond, paging may expand to neighbor tracking areas. Thus, if the UE does not respond to paging in the last known tracking area and the UE is using a neighbor list, the MME pages in areas comprising the neighbor list to locate the UE.